Oven timer



Jan. 19, 1965 F. A. sHoMAKER OVEN TIMER 3 Sheets-Sheet 1 FRANK A. SHOMAKER BY ,Qa/ff ATTORNEYS Jan. 19, 19'65 F. A. sHoMAKER OVEN TIMER 5 Sheets-Sheet 2 Filed Sept. 29. 1958 Jam 19, 1965 F. A. sHoMAKER OVEN TIMER 5 Sheets-Sheet 3 Filed Sept. 29, 1958 nu nnmllllllllllllh I Illll l'lllllljLlll Wai/VHS casing removed;

United States Patent O 3,166,242 @VEN TEMER Frank A. Shornaker, 308 Green Gorge Road, Signal Mountain, Tenn. Filed Sept. 29, 1953, Ser. No. 764,047 9 Claims. (Cl. 23S- 6D This invention relates to an oven timing mechanism, and in particular to a mechanism which will compute the total roasting time necessary for a particular item.

In determining the proper roasting or baking time an ite-m of food such as meat should be cooked, there are two variables which are normally known. The first of these is the weight of the item in pounds and ounces and the second is the time per pound the meat should be cooked for proper roasting. For example, if one purchases a 7 pound, 4 ounce roast, and Wishes to have 1t cooked to medium rare, by looking at a cooking chart it can be determined that the roast should be cooked at 325 for 19 minutes for each pound. This necessitates the cook multiplying 19 minutes by 7 pounds 4 ounces and then converting the product which will be in mlnutes to hours and minutes to set the standard automatic timer. It is the object of this invention to eliminate such computations by providing structure which will do 1t automatically.

It is ya further obiect of this invention to improve the eliiciency and convenient use of domestic and commercial ovens by providing a timer which takes much of the guesswork out of modern cooking. Greater accuracy is obtained because the tendency to estimate rather than compute cooking times will 'e decreased.

Itis a further object of the invention to provlde a sturdy arrangement of structure which can be used where it 1s necessary to combine two or more variables and have the output indicated by a definite mechanical movement.

It is a still further object of this invention to provide an arrangement of structure capable of multiplying a plurality of variables and have the resulting output of a physical movement capable of starting mechanisms Vsuch as a timing device.

The above expressly mentioned objectives are only indicative of the scope of the invention. Other valuable uses and objectives will become apparent upon a reading of the following specifications, in which:

FIG. l is an exploded view of a portion of the mechanism including the gear mechanism;

FIG. 2 is an exploded view of the remainder of the mechanism including the indicators and theV manual controls; Y

FIG. 3 is a front view of the timer showing the scales;

FIG. 4 is a top sectional View with portions of the FIG. 5 is a side View with portions of the casing removed;

FIG. 6 is a section taken along the line 6 6 of FIG. 5;

FIG. 7 is a partial sectional view taken along the line 7-7 of FIG. 5; and

FIG. 8 is a partial sectional View taken along the line 8 8 of FIG. 5.

Referring to FIG. 3, there is shown a transparent cover 17 having a hairline 15-etched on its surface. A knob 10, when turned in a-clockwise direction, is capable of placing a certain cooking time in minutes per pound represented on dial 26 under the hairline 15. The knob 10 has an :axially disposed recess 12 which receives the shaft 74, and another parallel axially offset recess 11 to receive the pin 3i).A A knob 13 when turned in a counterclockwise direction is capable of placing a certain value of weight logarithmically represented on dial 2S under the hairline 15. The calibrated dial 22, which shows 3,166,242 Patented Jan. 19, 1965 total cooking time, will turn as a result of the abovementioned inputs in a manner to be described below.

Referring now to FIGS. 1 and 2, there is shown a schematic gear train which is instrumental in describing this invention. The input through knob 10 will for convenience be referred to as input A, and the input through knob 13 for convenience will be referred to as input B. Gear 52 is supported on a shaft 5t). Input A moves gear 66 in a clockwise direction. This will cause the interior gear 70 to move a certain distance `along an arc as shown by the arrow D. The input B through knob 13 is counterclockwise and will cause gear B to move counterclockwise, which will transmit a movement through gears 40, 52, 54, 56 and 68. The gear 68 will rotate clockwise which will give an additional distance movement to gear 711 along the arc path D. The sum of these two logarithmic inputs is now represented by a certain distance movement along the arc D.

The distance movement along the arc D is converted to a rotary movement by rmly attaching the center of gear 711 to the periphery of follower 78 through a connecting member '72. Rotation of the follower 78 causes gears 82 and 84 to rotate. Rotation of gear 84 causes the gear cam 92 to rotate. Cam 92 is an antilog cam which converts the rotational logarithmic input into a true rotational output through gear 98.

Gear 55S is rigidly fastened to the shaft between gears 84 and 92. Rotation of gear 88 causes a rotation of gear 9i? which in turn is connected to calibrated dial 22 through the shaft 74 which is concentric to hollow shaft '76. Dial 22 is calibrated in a manner to place the total cooking time under the hairline 15.

The proportional rotational amount sent to dial 22 is also sent to the eccentric antilog cam 92. The peripheral contour of cam 92 is so designed that the rotational input given to its center by shaft 86 is converted to a true rotational output representing the sum of the logarithmic inputs when imparted to circular gear 98.

The rotation of gear 98 causes the rotation of cam 112. Cam 112 has a rise 113 adapted to engage and open a microswitch 134 which controls the heater and timer motor circuits. Cam 112 is fixedly secured to one-way slip clutch 114. The rotation of clutch 114 does not rotate bearing disc 116, although rotation of disc 116 will rotate slip clutch 114. When the timer is set, the rise 113 of cam 112 disengages with microswitch 134 causing the microswitch to close. After the timer has completed its cycle, the rise engages the microswitch and opens the heating circuit.

When rise 113 activates its adjacent niicroswitch, the clock motor begins operation. A rotation is imparted through shaft 129 from the motor to gear 128, gear 1211, shaft 122, and to bearing plate 116.

The rotation of plate 116 is imparted to slip clutch 114 which in turn drives the rest of the gear train in reverse until the pre-set time inten/al has elapsed. At this point, the rise 113 will de-activate the microswitch stopping the timing motor and de-energizing the controlled element. All dials will have returned to their original zero positions. A bearing 118 between 116 and 1211 is provided to Support a pin 122.

An exploded view of the mechanism is shown in FIGS. l and 2; FIGS. 5 and 6 show the mechanism assembled.

Knob 13 has a recess 14 therein adapted to receive pin 15' which rigidly connects knob 13 to dial 2S. Dial 2S in turn is rigidly connected to plate 62 by pin 4S. There isan arc-shaped slot in front wall 46 to permit the pin to perform this function. There are also matching avc-shaped siots in cover 17, dial 22, and dial 26 so that knob 13 may move dial 28. Spacingwashers 16, 2t), and 24 are provided between dials.

Plate 62 is rigidly connected to annular gear 66 by means of pins o4. Since all the connections are rigid, on a movement of knob 1?, there will be a like movement of dial 2S and annular gear do.

Knob luis connected directly to dial 26 and gear 3u by rod 3@ riding in bearing 34 and sleeve 36. Knob i3 will be rotated countercloclrwise to place a reading under the hairline and the movement will be carried through the gear train 3S, di), 52, 49, 56, 68 and finally imparting a clockwise angular movement to gear 7d. A bearing 4d is provided for pin l2 which connects gears dil and 52. A stub shaft 5i) is adapted to be attached to `spacing ber lo upon which gear 54 may rotate. Gear 7i?, then will reiect angular movements of knobs lil andi?) by linear movement along the arc path D. A dome shaped spacer 32 provides a housing for gears 38 and dil.

This linear movement is converted to -a rotation movement by'connecting the center of gear 7th to the periphery of gear '78 by means of pin 72. As described briefly above, this rotation is imparted to gear 82 through shaft 7d, and then to 84 and S8. Gear $8 in turn imparts it to gear 90. Gear @il is rigidly mounted on the end of shaft 74. Shaft 74 passes freely through the centers oi gear S2, plate 62, gear 78, sleeve 76, gear d3, gear 56, sleeve 5S, through each of the dials 28 and Ze, spacers 27 and 2d and is rigidly connected to dial 2?'. The sleeve 58 has a supporting ilange ed at one end thereof for easy attachment to plate 62. The shaft '7d then continues to knob l@ where it supports knobs 153 and i3 by recess l2. A dividing plate Si) adds rigidity to the framing members.

As described above, the rotation of gear 8d is transmitted to antilog cam 92. Due to the eccentricity of the cam it converts the logarithmic sum into a true rotational amount and imparts this amount to gear 9S. As best seen in FlG. 7, gear @S is biased into engagement with'carn 92 through the pivoted lever Miti and the spring 95. Yoke arms 102 are provided at either lend of the pivoted lever lo@ so that lever 10d is pivoted at one end and supports gear 98 at the other end thereof. This arrangement permits the gear 93 to oscillate .as Well as rotate with respect to the contours of cam 92.

This oscillating and rotating function of gear 98 requires it to be connected to cam 112 in a special manner. This connection is made by the spring shaft 99. This shaft, in order to accurately transmit the rotational movement, is made of a close-knit spiral spring capable of some lateral dellection, but is torsionally rigid. Spring shaft Si? accurately transmits the rotational movement of gear SiS to cam gear i12. The main housing for the timing unit is comprised of top plate 110, back wall 126, and bottom wall i3d. A sleeve 132 and a pin 124 are provided to support switching mechanism 134.

The cam 112 has ia rise 113 thereon to trip the microswitch i3d. The specific switch is of any `convenient design having multiple contacts and of itself forms no part of this invention.' lt must merely be capable of starting and stopping the timer clock and the controlled item in response to contact by rise 113. The signal to activate these circuits is of any conventional means, but a preferred manner is to transmit the signal to the timer 13d through wires 135 and transmit the signal to the heater orany time-controlled item through wires 137.

Through the use of the above invention, it can be seen that an operator of a domestic or commercial oven need only set the temperature control at the proper setting and then `set this timer control at the proper readings and everything then works automatically.

The invention described is inherently flexible in its operation. For instance, if one removed gear 54 from the gear chain yand proportioned gears 52 and 56 to mesh, the system would be capable of dividing as well as multiplying.

ln a general manner, while there has been disclosed in the above description, what is deemed to be a practical and eiiicient embodiment of the invention, it should be i well understood that the invention is not limited to such embodiment `as tiere might be changes made in the arrangement, disposition and form of the parts without departing from the principle of the present invention as comprehended Within the scope of the accompanying claims.

l claim:

l. In timer mechanisms, the combination including, control means tor a device to be regulated, said control means having an element shiftable between la zero position and a plurality of other positions and having an inactive condition in the zero position and an active condition in said other positions, the amount of said shift being a function of time, integrating means having lirst and second input means and at least one output means, said lirst input means having a zero position and including scale means having progressive values in accordance with a rst function oi time and being manually movable in one direction away from the Zero position to a predetermined setting to move said Voutput means'a iirst amount, said second input means having a zero position and including scale means naving progressive values in accordance with a second function of time and being manually movable in one direction away from the zero position to a predetermined setting to move said output means a second amount, said first and second amounts of movement of the output means being the product of the scale values of the setting oi the two input means, both said input means being movable in their respective reverse directions by reverse movement of said output means, means connecting said output means of the integrating means with said shiitable element of the control means to shift the element proportionally tothe movement of the output means, and conto stop said movement in said inactive condition.

2. in oven heating control mechanisms for an oven provided with heat-actuating means, the combination including, timing clock means having an element displaceable in one direction from a position at rest and including means to return said element to said rest position in an interval of time proportional to the amount of said displacement, actuating means being rendered effective by displace said element an amount proportional to a first functional value of time, logarithmic computer means including tirstmanually settable means having a position at rest and being movable from said rest position to another predetermined position in proportion to a lirst functional value of time, said computer means also iucluding second manually settable means having a position of rest and being movable from said rest position to another predetermined position in proportion to a second functional value of time, said computer means also including movable output means combining the movements of said first and second settable means in accordance with a prescribed ratio between said separate movements, and means connecting said output means with the displaceable element of the timing clock means.

3. The invention as defined in claim 2, wherein said output means includes visible indicia means movable with said output means and calibrated in accordance with the elapsed time represented by the amount of displacement of said element of the timing clock means. f

4. In timing control devices for electric switch means,l

the combination including, timing motor means provided with shaft means having an initial position and rotatable Y tion to return the shaft tothe initial position in said interi val of time, said electric switch means having actuator eans selectable for a first and a second condition of operation, means connected between said shaft means and said actuator means to select said first condition of operation when said shaft means is in its initial position and said second condition of operation when said shaft means is rotated away from the initial position, first and second manually movable indicator means each having an initial position and being movable in one direction away from said initial position, epicyclic gear train means having at least three relatively movable elements, said first and second indicator means being connected respectively with two of said gear train elements, and means operatively connecting said third gear train element with said shaft means of the timing motor means.

5. The invention as dened in claim 4,'wherein one of said three relatively movable elements of said gear train means comprises an antilogarithmic gear, and another of said three relatively movable elements comprises a gear meshing with said antilogarithmic gear and mounted on a movable pivot, whereby the ratio between the movement of said indicator means and said output means is non-linear.

6. The invention as defined in claim 4, wherein a third indicator means is included, and said gear train means includes a fourth element relatively movable with respect to said other elements, said fourth element being connected with said third indicator means.

7. In oven heat timing regulators, the combination including, a plurality of manually rotatable indicator means, planetary gear transmission means having a pluraiity of interconnected relatively movable elements, each of said indicator means being operatively connected with a respective movable element of the transmission means, timing means having rotating drive shaft means, movable scale means, and output means operatively connecting a respective movable element of the transmission means centrically mounted.

9. The invention as defined in claim 7, wherein said indicator means each includes circularly logarithmic scale means, and said output means includes a pair of shafts connected by mechanical antilog gearing means.

References Cited in the file of this patent UNITED STATES PATENTS 1,039,245 Bishop Sept. 24, 1912 1,889,876 Pellerin et al Dec. 6, 1932 1,920,877 Odatto Aug. 1, 1933 2,069,184 Hazard Ian. 26, 1937 2,293,175 Ruhl et al. Aug. 18, 1942 2,358,309 Batori Sept. 19, 1944 2,492,229 Le Blond et al Dec. 27, 1949 2,504,492 Brown Apr. 18, 1950 2,605,832 Mueller Aug. 5, 1952 2,733,764 Bliss Feb. 7, 1956 2,845,808 Stover Aug. 5, 1958 2,847,525 Everard Aug. 12, 1958 FOREIGN PATENTS 720,986 Germany Apr. 23, 1942 865,318 France Feb. 17, 1941 

1. IN TIMER MECHANISM, THE COMBINATION INCLUDING, CONTROL MEANS FOR A DEVICE TO BE REGULATED, SAID CONTROL MEANS HAVING AN ELEMENT SHIFTABLE BETWEEN A ZERO POSITION AND A PLURALITY OF OTHER POSITIONS AND HAVING AN INACTIVE CONDITION IN THE ZERO POSITION AND AN ACTIVE CONDITION IN SAID OTHER POSITIONS, THE AMOUNT OF SAID SHIFT BEING A FUNCTON OF TIME, INTEGRATING MEANS HAVING FIRST AND SECOND INPUT MEANS AND AT LEAST ONE OUTPUT MEANS, SAID FIRST INPUT MEANS HAVING A ZERO POSITION AND INCLUDING SCALE MEANS HAVING PROGRESSIVE VALUES IN ACCORDANCE WITH A FIRST FUNCTION OF TIME AND BEING MANUALLY MOVABLE IN ONE DIRECTION AWAY FROM THE ZERO POSITION TO A PREDETERMINED SETTING TO MOVE SAID OUTPUT MEANS A FIRST AMOUNT, SAID SECOND INPUT MEANS HAVING A ZERO POSITION AND INCLUDING SCALE MEANS HAVING PROGRESSIVE VALUES IN ACCORDANCE WITH A SECOND FUNCTION OF TIME AND BEING MANUALLY MOVABLE IN ONE DIRECTION AWAY FROM THE ZERO POSITION TO A PREDETERMINED SETTING TO MOVE SAID OUTPUT MEANS A SECOND AMOUNT, SAID FIRST AND SECOND AMOUNTS OF MOVEMENT OF THE OUTPUT MEANS BEING THE PRODUCT OF THE SCALE VALUES OF THE SETTING OF THE TWO INPUT MEANS, BOTH SAID INPUT MEANS BEING MOVABLE IN THEIR RESPECTIVE REVERSE DIRECTIONS BY REVERSE MOVEMENT OF SAID OUTPUT MEANS, MEANS CONNECTING SAID OUTPUT MEANS OF THE INTEGRATING MEANS WITH SAID SHIFTABLE ELEMENT OF THE CONTROL MEANS TO SHIFT THE ELEMENT PROPORTIONALLY TO THE MOVEMENT OF THE OUTPUT MEANS, AND CONSTANT SPEED MOTOR MEANS CONNECTED WITH SAID OUTPUT MEANS, SAID MOTOR MEANS INCLUDING MEANS RESPONSIVE TO AN ACTIVE CONDITION OF SAID CONTROL MEANS TO MOVE SAID OUTPUT MEANS IN SAID REVERSE DIRECTION AT SAID CONSTANT RATE OF SPEED AND TO STOP SAID MOVEMENT IN SAID INACTIVE CONDITION. 